Groovy: Lombok的@NoArgsConstructor未创建默认构造函数

Question

我正在使用 lombok 1.18.6 在我的 spring boot 项目中，我有 @NoArgsConstructor ，但仍然出现错误 org.springframework.orm.jpa.JpaSystemException: No default constructor for entity: : com.validation.entity.Client; nested exception is org.hibernate.InstantiationException: No default constructor for entity: : com.validation.entity.Client] with root cause

下面是我的 Client 实体

import lombok.AccessLevel
import lombok.Data
import lombok.NoArgsConstructor
import org.hibernate.annotations.Fetch
import org.hibernate.annotations.FetchMode
import org.hibernate.annotations.Nationalized
import javax.persistence.CascadeType
import javax.persistence.Column
import javax.persistence.Entity
import javax.persistence.GeneratedValue
import javax.persistence.GenerationType
import javax.persistence.Id
import javax.persistence.OneToMany

@Data
@NoArgsConstructor(access = AccessLevel.PUBLIC)
@Entity
class Client implements Serializable {

    private static final long serialVersionUID = 1L

    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Long id

    @Nationalized
    @Column(unique = true, nullable = false)
    private String name

    @Column(nullable = false)
    private boolean active

    @Nationalized
    @Column(unique = true, nullable = false)
    private String externalId

    @Fetch(value = FetchMode.SELECT)
    @OneToMany(mappedBy="client", cascade=CascadeType.ALL, targetEntity = RuleSet.class)
    private Set<RuleSet> ruleSets

    Client(String name, boolean active, String externalId){
        this.name = name
        this.active = active
        this.externalId = externalId
    }
}

以下是我的ClientRepository。

import com.validation.entity.Client
import com.validation.entity.RuleDefinition
import org.springframework.data.repository.CrudRepository
import org.springframework.data.repository.PagingAndSortingRepository
import org.springframework.data.repository.query.Param

interface ClientRepository extends PagingAndSortingRepository<Client, Long> {

    Client findByName(@Param("name")String name)

    Client findByNameIgnoreCase(@Param("name")String name)

    Client findByExternalId(@Param("lawId")String id)

    Client findByExternalIdIgnoreCase(@Param("lawId")String id)

    Client findByRuleSetsId(Long id)

    Set<Client> findByNameIgnoreCaseOrExternalIdIgnoreCase(@Param("name")String name,@Param("lawId")String id)

    Set<Client> findByNameContainingIgnoreCase(@Param("name")String name)

}

请问有人能帮我解释一下，为什么即使加了@NoArgsConstructor(access = AccessLevel.PUBLIC)，我仍然会得到No default constructor for entity的错误？

以下是当我向https://localhost:9443/api/clients发出GET请求时的完整stacktrace：

2019-03-22 11:46:44 - Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.orm.jpa.JpaSystemException: No default constructor for entity:  : com.validation.entity.Client; nested exception is org.hibernate.InstantiationException: No default constructor for entity:  : com.validation.entity.Client] with root cause
org.hibernate.InstantiationException: No default constructor for entity:  : com.validation.entity.Client
    at org.hibernate.tuple.PojoInstantiator.instantiate(PojoInstantiator.java:85)
    at org.hibernate.tuple.PojoInstantiator.instantiate(PojoInstantiator.java:105)
    at org.hibernate.tuple.entity.AbstractEntityTuplizer.instantiate(AbstractEntityTuplizer.java:673)
    at org.hibernate.persister.entity.AbstractEntityPersister.instantiate(AbstractEntityPersister.java:4946)
    at org.hibernate.internal.SessionImpl.instantiate(SessionImpl.java:1682)
    at org.hibernate.internal.SessionImpl.instantiate(SessionImpl.java:1666)
    at org.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:1663)
    at org.hibernate.loader.Loader.getRow(Loader.java:1561)
    at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:731)
    at org.hibernate.loader.Loader.processResultSet(Loader.java:990)
    at org.hibernate.loader.Loader.doQuery(Loader.java:948)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:340)
    at org.hibernate.loader.Loader.doList(Loader.java:2689)
    at org.hibernate.loader.Loader.doList(Loader.java:2672)
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2506)
    at org.hibernate.loader.Loader.list(Loader.java:2501)
    at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:504)
    at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:395)
    at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:220)
    at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1508)
    at org.hibernate.query.internal.AbstractProducedQuery.doList(AbstractProducedQuery.java:1537)
    at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1505)
    at org.hibernate.query.Query.getResultList(Query.java:135)
    at org.hibernate.query.criteria.internal.compile.CriteriaQueryTypeQueryAdapter.getResultList(CriteriaQueryTypeQueryAdapter.java:74)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.readPage(SimpleJpaRepository.java:569)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.findAll(SimpleJpaRepository.java:388)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.findAll(SimpleJpaRepository.java:356)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.data.repository.core.support.RepositoryComposition$RepositoryFragments.invoke(RepositoryComposition.java:359)
    at org.springframework.data.repository.core.support.RepositoryComposition.invoke(RepositoryComposition.java:200)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$ImplementationMethodExecutionInterceptor.invoke(RepositoryFactorySupport.java:644)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:608)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lambda$invoke$3(RepositoryFactorySupport.java:595)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:595)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:294)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:135)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
    at com.sun.proxy.$Proxy134.findAll(Unknown Source)
    at org.springframework.data.repository.support.PagingAndSortingRepositoryInvoker.invokeFindAll(PagingAndSortingRepositoryInvoker.java:74)
    at org.springframework.data.rest.core.support.UnwrappingRepositoryInvokerFactory$UnwrappingRepositoryInvoker.invokeFindAll(UnwrappingRepositoryInvokerFactory.java:158)
    at org.springframework.data.rest.webmvc.RepositoryEntityController.getCollectionResource(RepositoryEntityController.java:202)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:189)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:800)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1038)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:90)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:117)
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:106)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1417)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)

以下是反编译的Client类。

import groovy.lang.GroovyObject;
import groovy.lang.MetaClass;
import java.io.Serializable;
import java.util.Set;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import org.codehaus.groovy.runtime.callsite.CallSite;
import org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation;
import org.codehaus.groovy.runtime.typehandling.ShortTypeHandling;
import org.hibernate.annotations.Fetch;
import org.hibernate.annotations.FetchMode;
import org.hibernate.annotations.Nationalized;

@Entity
public class Client
  implements Serializable, GroovyObject
{
  private static final long serialVersionUID = 1L;
  @Id
  @GeneratedValue(strategy=GenerationType.IDENTITY)
  private Long id;
  @Nationalized
  @Column(nullable=false, unique=true)
  private String name;
  @Column(nullable=false)
  private boolean active;
  @Nationalized
  @Column(nullable=false, unique=true)
  private String externalId;
  @Fetch(FetchMode.SELECT)
  @OneToMany(targetEntity=RuleSet.class, mappedBy="client", cascade={javax.persistence.CascadeType.ALL})
  private Set<RuleSet> ruleSets;

  public Client(String name, boolean active, String externalId)
  {
    MetaClass localMetaClass = $getStaticMetaClass();this.metaClass = localMetaClass;String str1 = name;this.name = ((String)ShortTypeHandling.castToString(str1));
    boolean bool = active;this.active = DefaultTypeTransformation.booleanUnbox(Boolean.valueOf(bool));
    String str2 = externalId;this.externalId = ((String)ShortTypeHandling.castToString(str2));
  }
}

- OTUser

---

access = AccessLevel.PUBLIC is redundant for NoArgsConstructor - Karol Dowbecki

@KarolDowbecki 添加 access = AccessLevel.PUBLIC 只是为了确保它不会引起任何问题。 - OTUser

你是如何构建这个项目的？其他 Lombok 注解，比如 @Getter，是否也在工作？ - Karol Dowbecki

嗯..有com.wkelms.ebilling.validation.entity.Client和com.validation.entity.Client？为了确保，请在您的源代码片段中添加包。 - pirho

你能否检查一下是否用@Canonical替换@Data和@NoArgsConstructor来解决你的问题呢？ - Krzysztof Atłasik

Answer 1

根据您的反编译输出，您正在使用 Groovy 而不是 Java。Lombok 与 Groovy 不兼容。据您的反编译代码显示，没有 Lombok 的增强，例如 @Data 并未创建 getter。

如果您打算继续混合使用 Lombok 和 Groovy，那么您需要重新审视您的项目设置。个人建议不要混用这两种语言。

- Karol Dowbecki

---

将Client类设置为public，但仍然出现相同的异常。 - OTUser

请发布完整的堆栈跟踪。同时使用javap -v或de-lombok检查.class文件。这可能与Lombok无关，1.18.6对我有效。 - Karol Dowbecki

Answer 2

请尝试这个方法，它对于@NoArgsConstructor有帮助。现在lombok可以正常工作且没有错误显示。

除依赖项之外，还需添加Lombok插件，如下所示：

plugins {
  id "io.freefair.lombok" version "6.4.1"
}
    
dependencies {
  implementation 'org.projectlombok:lombok:1.16.18'
}

祝你有美好的一天！享受编程吧！

- SonjaJan

---

请查看此链接：https://plugins.gradle.org/plugin/io.freefair.lombok - SonjaJan

Answer 3

上面提到的“Lombok与Java不兼容”的说法是不正确的，实际上Lombok与Java非常兼容，就像Lombok与Groovy不兼容所说的那样。

在Groovy代码中使用Lombok注释的Java对象没有问题，可以参考这里的示例here。

Groovy代码中的Lombok注释会被简单地忽略掉。Groovy不支持Lombok注释，因此这更多是Groovy的问题而不是相反。

这相对化了不要同时使用两者的说法。我认为这正是基于JVM的语言的整个重点：良好的“相对”互操作性（Java、Groovy、JRuby、Kotlin等）。

- Christoph Henrici